1. Field of the Invention
This invention relates to electronically controlled sewing machines and more specifically to sewing machines having electronically controlled feed reversing devices for shifting the feed regulating mechanism into a mode for backtacking.
2. Description of the Prior Art
The use of switches for controlling the reversing of the feed regulating mechanism of a sewing machine is known in the prior art. See for example U.S. Pat. No. 3,977,338 of John W. Wurst et al which is owned by the assignee of this invention.
One problem associated with prior art backtacking mechanisms is that they typically require an operator to hold the switch depressed, thereby preventing the use of two hands to guide the workpiece.
Another problem with prior art backtacking controls is that they cannot be selectively locked in the backtack mode for completing lengthy backtack cycles.
It is therefore an object of this invention to provide an arrangement which will permit a sewing machine operator to select a continuous or a momentary backtack mode with only a single switch.
It is also an object of this invention to provide a backtack selection circuit which is compatible with electronic logic circuitry.
Still another object is to allow a sewing machine operator to backtack without having to hold a button while sewing.
An additional object is to construct a backtack control with a minimum number of additional circuit components.